Process for manufacturing rubber boots



y 0, 1929. A. A. GLIDDEN ET AL 1,722,697 I PROCESS FOR MANUFACTURING RUBBER BOOTS Filed Aug. 23, 1927 I Patented July 30, 1929.

, UNITED STATES ATE-KNT' OFFICE.

ALFRED A. GLIDDEN AND THOMAS M. KNOWLAND, OF WATERTOWN, AND HERBERT L.

DAVIS, OF WALPOLE, MASSACHUSETTS, ASSIGNORS TO HOOD RUBBER COMPANY,

OF WATERTOWN, MASSACHUSETTS, A CORPORATION OF MASSACHUSETTS.

PROCESS FOR MANUFACTURING RUBBER BOOTS.

Application filed August 23, 1927. Serial No. 214,942.

This invention relates to an improved process for manufacturing rubber boots, the principal steps of the process comprising building a rubber boot upon a hollow boot treeof .5 expandible material which .has preferably drawn thereovera rubber boot lining of expandible. material, such as, a knitted stockmg; then placing the assembled tree; boot lining and boot in a heated mold until the boot is cured, and then removing it from the mold, together with the tree, and then removing the boot with its lining from the tree.

The invention consists in the improved process and-in the various novel steps in the process, set forth in the following specifics tion and particularly pointed out in the-- claims.

Referrin to the drawings Figure 1 1s a side elevation of a boot lining. Fig. 2 is a sectional elevation of an expandible boot tree. J

Fig. 3 is a side elevation of the boot tree with the boot lining placed upon the treeand shown in section.

Fig. 4 is a side elevation of a boot positioned on an expandible tree and showing a portion of the boot lining and tree.

Fig. 5. is a sectional plan illustrating the boot tree, lining and boot positioned in a mold.

Like numerals refer to like parts throughout the several views of the drawings. I

In the drawings, 5 is an expandible boot tree, the. same forming the subject-matter of an application for United States Letters Patent on boot tree filed August 22, 1927, by Alfred A. Glidden, Thomas M. Knowland and Herbert L. Davis Serial No. 214,622, and consisting of'a hollow body member comprisin a leg portion 7, foot portion 8 and closed end portion 9. The hollow body member may be constructed of any suitable expandible waterroof material as,'for example, vulcanize rubber.

Located in the closed end portion 9 of the body member is a flanged sleeve 10, said sleeve being externally threaded to receive a nut 11 by means of which the sleeve is tightly .clamped to the material comprising the tree.

The outer end of thesleeve 10 is detachabxlfy connected by means of a union 12 with a branch pipe fitting 13, a nipple 14 being interposed between said pipe fittmg and the union.

vclude the leg and'foot portions of the boot distance into the body mem er of the tree.

A flexible tube 18 is detachably secured to the outer end of the inlet pipe 17 Surrounding the exterior of the inlet pipe 17 is an outlet passage 19, the latter extending through the ilaeve 10, union l2, nipple 14 and ipe httin A flexible tube 20 is detacha 1y secure to the bushing 16.

In the carrying out of our improved process, the first step is to paint the outside of theexpandible tree 5 with a micasolution or the like, so that after the boot has been cured it may be easily removed from the tree. A stocking 21 of elastic material, such as, knitted fabric, illustrated in Fig. 1, is then drawn over the boot tree 5, as illustrated in Fig. 3. This'stocking constitutes the lining of the boot when completed. The different parts of which'the boot is composed are then built upon the ling covered boot tree in a mannerwell known to those skilled in the art and inand the sole and heel. The boot is then rubbed down with a fine powder-like material, such as, talc. The object of this step in the process is to prevent air from being trapped between the outer surface of the rubber boot and the inner surface of the mold, thereby forming pockets which would be injurious to the appearance of the finished boot.

The mold 22, into which the boot is to be placed, is illustrated in Fig. 5 and consists fundamentally of two sides 23 and heating plates 24. After rubbing the boot down with a suitable powder-like material, the mold 22 is cleaned, and has its inner surface dusted with asbestine or the like. The boot, together with the tree and the lining in assembled condition, are then placed in' the heatedmold and the mold locked.

The boot is inflated either with air underpressure through the inlet pipe 17, or with water,.preferably heated and under pressure, through the pipe, 17. Where heated water is used it circulates through the boot tree 5 and passes out through the passage 19; where air is used it is not necessary that it should circulate.

The mold 22 is heated by electrical means to a predetermined degree. After the boot has remained in the mold a suflicient length of time to become cured by the heat, the tree is deflated by removing the pressure of air or water, as the case may be. The mold is then unlocked, the boot is removed from the mold and stripped from the tree. The overflow from the tap and heel of the boot is then ground oflt'and the overflow and thetop of the boot are trimmed with scissors. The boot is then polished and otherwise rendered in condition for the market.

If desired, the herein described process may be carried out without the lining for the boot, in which case the different parts of which the boot isconstructed would be built up directly on the boot tree instead of upon the lining superimposed upon said boot tree.

If desired, the curing process may be carried out by heating the mold and omitting the heating of the boot from the inside thereof, but it is considered much moresatisfactory to employ the heating of the mold and the heating of the boot from the interior by means of heated fluid supplied to the tree than it is 'to use either one of these heating means alone, the result in the process being more satisfactory on account of a greater rapidity and efliciency in the heating andcuring operation being obtained where both means of heating are employed.

The mold preferably used in the carrying out of our improved process is made the subject matter of another a pl-ication for 'United States Letters Patent or mold for rubber boots filed August 23, -1927 by Alfred A. Glidden, Howard G. Ellis and Herbert L.

Davis, Serial No. 214,941, and the lining is also made the subject matter of another application for -United States Letters Patent for lining for rubber boots and 'method' of manufacturing, filed by Alfred A. Glidden and Frank R. McKenzie on July 26,1927, v

Serial No. 208,567.

In the specification and clalmsthe word rubber has been used in connection with the materialnf the boot which is to be formed and cured, but it is evident that any other material which is a substitute for rubber or the various compounds thereof may be used without departing -from' the spirit of this erably accomplished by electrical means, and ;by this. means an even degree ofhcat of the .ing a powder-like material to the outer surdesired temperature may be maintained, all as fully described in-said application mold for rubber boots. It is evident that the boot may be placed in a mold and the mold then heated and kept heated until the boot is cured, but the prferred manner of procedure is to have the mold heated first and then the boot placed in the heated mold and the mold keptheated until the boot is cured.. As stated, however,

the boot may be placed in a mold and the mold then heated and kept heated until the boot is cured.

By employing the process hereinbelore described, the boot lining is brought into contact with and pressed into the interior surface of the rubber boot throughout every portion thereof, leaving the same smooth and firmly attached to and embedded in the rubber of which the boot is constructed. v

While the mold has been described as being heated by electrical means, it is evident that that the same may be heated by means other than electrical without departing from the spirit of this invention.

We claim:

1 1., The process of manufacturing rubber boots which comprises pulling a lining for a rubber boot over a hollow boot tree of eX-. pandible material; then building a rubber boot on said lining covered tree; then placing the assembled boot tree, lining and boot in a heated mold for rubber boots; then closing the mold; then inflating the boot tree, lining and boot; then leaving the boot tree, lining and boot in the mold until the boot is cured;

then deflating the tree; then removing the boot and lining and tree from the mold, and

then removing the boot and its lining from thetree.

2. The process of manufacturing rubber boots which comprises pulling a lining for a rubber boot over a hollowboot tree of expandiblematerial; then building a rubber boot on said lining covered tree; then placing the assembled boot tree, lining and boot in r a heated mold for rubber boots; then closing the mold; then inflating the boot tree, lining and boot with a heated fluid; then leaving the boot tree, lining and boot in the mold until the boot is cured; then deflating the tree; then removing the boot and lining and tree from the mold, and then removing the boot and its lining from the tree.

V 3. The process of manufacturing rubber rubber boot over a hollow boot tree of expandible material; then building arubber oot on said lining covered tree; then applyface of the-boot; then placing'the assembled boot tree, lining and boot in a heated mold for rubber boots; then closingthe' mold; then inflating the boot tree, lining and boot; then leaving the boot tree, lining and boot in the boots which comprises pulling a lining for a rubber boot. 7

mold until the boot is cured then deflating the tree; then removing the boot and lining and tree from the mold, and then removing the boot and its lining, from the tree.

4. A step in the process of manufacturing rubber boots which consists in pulling a lining for a rubber boot over a hollowboot tree of expandible material.

5. A step in the process ofmanufacturing a rubber boot which consists in building a' rubber boot on a hollow boot tree of expandible material covered with a lining for a 6. The process of manufacturin rubber boots which comprises painting the outer surface of a hollow boot tree of ex audible material with mica solution or the li e; then pullinga lining for a rubber boot over the said hollow boot tree; then building a rubber and boot in the mold until the boot is cured;

then deflating the tree; then removing the boot and lining and tree from the mold; and

then removing the boot and its lining from v the tree.

In testimony whereof we have hereunto set our hands.

ALFRED A. GLIDDEN. THOMAS M. KN OWLAND. HERBERT L. DAVIS. 

